ALMA opens its eyes 'wide' and reveals its first image

3 October 2011

The Antennae Galaxies (also known as NGC 4038 and 4039) are a pair of distorted colliding spiral galaxies about 70 million light-years away. This image combines observations made with ALMA and the Hubble Space Telescope. Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope.

ALMA, the Atacama Large Millimetre/sub-millimetre Array), the most complex ground based telescope in existence, is officially open to astronomers and has produced its first image.

This comes after more than a decade of design and construction involving technological and scientific expertise from countries across four continents, including the UK. The project is technologically state-of-the-art, with numerous individual components from all over the globe having been brought together to make ‘first science’ possible. The scale of this achievement is demonstrated by the fact that the number of observing proposals on ALMA has outweighed availability nine times over – already setting a record for a telescope. In return for the UK’s investment in the project, UK scientists have access to ALMA through STFC’s subscription to the European Southern Observatory and the project has seen the UK’s technical capabilities and expertise strengthen both within academia and industry.

ALMA is a huge high-frequency observatory that will eventually comprise 66 individual telescopes that are combined electronically to simulate a telescope diameter of up to 16km – more than a thousand times the diameter of a single individual telescope within the array. It reveals a view of the Universe that cannot be seen at all by visible-light and infrared telescopes. It observes ‘light’ emitted in the millimetre and submillimetre wavelength range, roughly one thousand times longer than visible-light wavelengths. Using these longer wavelengths allows astronomers to study extremely cold and visibly opaque objects in space - such as the dense clouds of cosmic dust and gas from which stars and planets form - as well as very distant objects from the early Universe.

'Even in this very early phase ALMA already outperforms all other submillimetre arrays. Reaching this milestone is a tribute to the impressive efforts of the many scientists and engineers in the ALMA partner regions around the world who made it possible,' said Tim de Zeeuw, Director General of ESO, the European partner in ALMA.

'I am not at all surprised to see the huge number of proposals to use ALMA which have been written by astronomers in the UK and throughout the world astronomical community. ALMA brings a completely new of the Universe and will revolutionise our understanding of our celestial origins. The excitement begins now!' said John Richer, UK Project Scientist for ALMA, based at the University of Cambridge.

Gary Fuller, Principal Investigator at the UK ALMA Regional Centre Node, based at The University of Manchester added: 'Projects like ALMA require an enormous amount of patience - many of us have been working on this for more than a decade. There have been many obstacles to be overcome, but I've no doubt that it will all be worth it - it's great to see the first scientific observations beginning for astronomers from the UK and around the world.'

UK involvement in ALMA includes STFC’s Rutherford Appleton Laboratory and UK Astronomy Technology Centre, the Cavendish Laboratory at the University of Cambridge, the University of Manchester and the University of Kent, all of whom played key roles in the design and construction of ALMA.

Science Minister David Willetts said, 'The ALMA telescope is an incredibly impressive feat of science and engineering, and it’s fantastic that the UK has played such a significant role in its design and construction. Our involvement has ensured our leading researchers have access to the most state-of-the-art observation technology, keeping us at the cutting edge of astronomy research.'

John Richer said: 'ALMA is an awe-inspiring piece of engineering: every aspect of it is state-of-the-art. For example, the antennas use innovative carbon fibre designs to keep their shapes precise to only a few microns, less than the width or a human hair, even in hostile weather conditions. The superconducting receivers have to amplify very high-frequency radio signals without adding too much noise. The central correlation computer has to process vast volumes of digital data from the receivers, a data rate that exceeds total internet traffic of the UK. And finally this all has to be done on a very remote site, deprived of oxygen due to its very 17,000-feet altitude.'

Brian Ellison, UK Project Manager for ALMA said: 'First science is a fantastic achievement for the project and also for UK scientists and technologists. The benefit to the UK is highly significant with the UK making major contributions to key ALMA infrastructure through the provision of services, hardware and software. What’s more, the technological expertise gained from ALMA construction is already proving hugely valuable in other areas of application such as Earth observation and imaging'.

The ALMA team has been busy testing the observatory’s systems over the past few months, in preparation for the first round of scientific observations, known as Early Science. One outcome is the first image published from ALMA, albeit from what is still very much a growing telescope. Most of the observations used to create this image of the Antennae Galaxies were made using only twelve antennas — far fewer than will be used for the first science observations — and with the antennas much closer together. Both of these factors make the new image just a taste of what is to come. As the observatory grows, the sharpness, speed, and quality of its observations will increase dramatically as more antennas become available and the array grows in size.

ALMA could accept only about a hundred or so projects for this first nine-month phase of Early Science. Nevertheless, over the last few months, keen astronomers from around the world have submitted over 900 proposals for observations. The successful projects were selected by international peer review involving 50 of the world's leading astronomers.

Further information

The University of Manchester's Jodrell Bank Centre for Astrophysics hosts the UK ALMA Regional Centre node which provides support for UK scientists using ALMA.

Jodrell Bank carries out research and technogy development in the area of digital fibre optic transmission. This has been applied to our own e-MERLIN telescope and to ALMA which also connects its separate antennas by fibre links